Generalized spectroscopic ellipsometry and Mueller-matrix study of twisted nematic and super twisted nematic liquid crystals

Generalized spectroscopic ellipsometry (g-SE) and Mueller-matrix (MM) measurements are applied to twisted nematic (TN) and super twisted nematic (STN) displays. Transmitted measurements near normal incidence are used to extract twist, φ(d), and anisotropy for each display type. Angle-dependent measurements are used to determine tilt distribution, θ(d). Oblique angle measurements allow characterization of both ordinary and extraordinary indices. Finally, the liquid crystal layer thickness is accurately determined from coherent interference oscillations.